Adjoint-based sensitivity analysis of a reactive jet in crossflow

Abstract

With current advances in computational resources, high- delity simulations of reactive

ows are increasingly being used as predictive tools in various industrial applications. In order to accurately capture the combustion process, detailed/reduced chemical mechanisms are employed, which in turn rely on various model parameters. Therefore, it would be of great interest to quantify the sensitivities of the predictions with respect to the introduced models. Due to the high dimensionality of the parameter space, methods such as nite di erences which rely on multiple forward simulations prove to be very costly, and adjoint-based techniques are a suitable alternative. The complex nature of the governing equations, however, renders an e cient strategy in nding the adjoint equations a challenging task. In this study, we employ the modular approach of Fosas de Pando et al. (2012) to build a discrete adjoint framework applied to a reacting jet in cross ow. The developed framework is then used to extract the sensitivity of the integrated heat release with respect to the existing combustion parameters. Analyzing the sensitivities in the three-dimensional domain provides insight toward the speci c regions of the ow that are more susceptible to the choice of the model. Masking functions are also employed in order to isolate speci c regions within the computational domain for analysis.